The product has seven parts, namely, retractor, flexible connector, tongue guard, connecting arm, suction tubing, position block, and Y-connector.( Detailed structure is in assemble instruction). Before operation, dentists need to put the retarctors on both sides of patient’s lips to maintain the mouth opening so that patient will not feel too tired. Meanwhile the tongue guard can effectively restrict the activities of the tongue. The mouth bottom is just below the suction area, which can maximize the absorption of the saliva and prevent moisture. This product can create a relatively dry environment for dentists. It’s mainly used for orthodontic treatment.